Telegraph communication system



May 3, 1932.

TELEGRAPM COMMUNICATION SYSTEM Filed June 2l, 1950 3 Sheets-Sheet l /Nl/E/von D. B. PE PRY A TTORNEV D. B. PERRY i 1,856,224

TELEGRAFH COMMUNI CAT ION SYSTEM Filed June 21, 1950 3 Sheets-Sheet 2 1NVENT0R D. B. PERRY ATTORNEY May 3, 1932. D, B, PERRY 1,856,224

TELEGRAPH COMMUNI CATION SYSTEM Filed June 21, 1930 5 Sheets'-Sheet 3 R&$ "-62 /N VEN TOR D. B. PERRY ATTORNEY L :j v l @mlm Patented May 3, 1932 UNITED STATES PATENT OFFICE DONALD PERRY, OF HAYLEWOOD, NEW JERSEY, ASSIGNOR T AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A. CORPORATION OF NEW YORK TELEGRAIH COMMUNICATION SYSTEM Application led June 21, 1980. Berial No. 488,890.

This invention relates to printing teleraph switching systems and more particu- Iarly to a system which has a central station capable of broadcasting to a plurality of other stations.

A primary object of this invention is to reduce a telephone typewriter system wherey an instrument at one of several switchhoards may send a message which will be received and recorded in t pewritten form on a selected few or on al machines connected to the system.

Another object is to provide means :for controlling the apparatus at all switchboards in the system from a remote central switchhoard and for visually indicatin to the operator at the central switchboar the pro er v'iunctioning of the apparatus at each o ce.

A feature of this invention is a special circuit arrangement located at each oilice for conditioning the apparatus at that office to automatically rebroa cast messages to a group ot stations.

A -turther feature is the use of circuit means whereby the central switchboard may obtain control of each local switchboard.

lin general, the switching system to be described comprises a central switchboard conncctcd to several distant local switchboards. lEach ot these, in turn, is connected through branch circuits with the various local receiving stations of which it forms the central point. Telegraph channels are utilized to connect the central switchboard with all the local switchboards. These channels may be used singly or simultaneously and over them it is possible to carry on two-way simultaneous (duplex) service.

A system of this type is especially' adapted For use in police work and in business concerns where it is necessary to send information to many distant localities simultaneously and iu a quick and eiiicicnt manner. The operator at the machine simply types the message ou a keyboard similar to that of a standard typewriter and what is typed is automatically recorded on the receiving machines. 'In this manner a permanent record is made by both the transmitting and receiving machines.

Bassum' In the accompanying drawings Fig. 1 shows diagrammaticall the eneral arrangement of a radial printing te e raph sys- Eem embodying the features of t is invenion; J

Fig. 2 shows in detail the circuit diagram of the central switchboard or general headquarters of the system' and Fig. 3 shows in detail the circuit diagram of thelocal or division headquarters.

General features of the system The principal function of Fig. 1 isto enable the reader to uickly comprehend the manner in which t e` various circuit diagrams, tobe explained later, are connected with the system as a whole.

The telegraph system shown in Fig. 1 comprises a central 0r general headquarters station A and two division stations B and C. Each station is equipped with a switchboard 1 having normally associated therewith a printing telegraph transmitting and receivmg set 2. From each stati on telegraph lines 3 extend to receiving only sets 6. A one-wa polar repeating station 4 is provided for eac telegraph line 3. Two-way telegraph channels 8 connect each division station with the central station A. These channels may be either full duplex or two one-way channels over which two-way simultaneous service may be carried on. At each station a receiving set 9, individual to each telegraph channel 8, is provided. Repeaters maybe inserted in these channels if desired. The repeaters may be full duplex, one-way or any of the repeaters commonly used and well known in the telegraph art for two-way simultaneous communication.

The repeater 4 may be located at the switchboard or at a special repeater boardl located near the station.

At central station A, a special remote control code or selector key 7 is rovided for transmitting a series of code impulses for conditioning the switchboard apparatus at each division station for automatically rebroadcasting messages received over the telegraph channels 8.

Although only two division stations are shown in Fig. 1, as many division stations may be provided as are considered desirable or necessary for a particular telegraph switching system. Several receiving sets 6 may be arranged in series with anyparticular telegraph line 3.

In general, the operation of selector ke?l 7 at general headquarters will actuate the re ay equipment at all the division headquarters to which the central station desires to broadcast. This relay equipment will retransmit thejy incoming signals to all the receiving sets connected to the switchboard of whch it forms the central point. At the same time, general headquarters may broadcast the signals to the receiving sets connected to its own station if it so desired. The switchboard at station A is so arranged that by means of keys it may transmit to a .selected few or all division stations connected to the system. If general headquarters wishes to communicate with any or all division headquarters without broadcasting to the receiving stations associated with the respective division switchboards this may lbe done by transmitting from general headquarters without operating code selector key 7.

In addition, receiving sets 9 are provided at the central switchboard A and at the re` spective division switchboards for connection in each telegraph channel 8 associated with each division. In broadcasting from central station A, each of the sets 9 located at A is actuated by the proper functioning of the apparatus at the respective division station to which the set is connected by its respective telegraph channel 8. In this manner, headquarters is provided with a visual typewritten record of the message being broadcast and' automatically retransmitted back over the telegraph channel 8 as an indication of the proper functioning of the apparatus at each oice.

The detailed operation of the system will now be explained in connection with Figs. 2 and 3.

Broadcasting from general headquarters Fig. 2 taken together with Fig. 3 and placed to the left of Fig. 3 shows a schematic circuit of the general headquarters station equipment as well as that of the equipment at a division station. In connection with these figures, the circuit operation will first be considered for broadcasting a message from general headquarters (Fig. 2) to one or more division stations (Fig. 3). Only two telegraph channels and two receiving stations are shown connected to the central switchboard.

Assuming that the operator at general headquarters desires to broadcast a message through the division headquarters to the receiving stations associated with the divisions, code selector key 7 will be operated. The

operation of code key 7 through one revolution Will transmit a series of special break and make signals by causing spring 11 of the key to make and break contact with insulated bushings 10 and 100 thus opening and closing the operating path for relay 12. Re-

lay 12 is a special master relay with two I' windings and is normally held operated to its marking position on a circuit from battery through the upper winding of relay 12 to ground through the sending and reeeiv ing printer 13 and the contact of code key 7 Current through the lower or biasing winding tends to operate relay 12 against its spacing contact. The strength lof the current flowing through the upper winding is greater than the biasing current and holds the ar' -Resistances 40 and 41 connect the marking and spacing contacts, respectively, 12 to battery 18. is grounded.

As the armature of relay 12 operates, in accordance with signals transmitted from printer 13 or from code selector key 7, it causes the spacing and marking contacts of relay 12 to be grounded alternately. With the armature thereof on the spacing contact, current Hows from battery 18 through resist ance 40 through the windings of all the sending relays in series and thence to ground through the spacing contact and armature of relay 12. All the sending relays 14, 15, 16 and 17 are then operated against their respective spacing contacts. When the armature of relay 12 moves to its marking contact. the direction of current flow through the windings ofthe sending relay is reversed, the current flowing now through resistance 41 and through the windings of the sending relays in series to ground through the marking contact and armature of relay 12. The sending relays are thus operated against their respective marking contacts. In this way, all the sending relays are caused to `operate, simultaneously, and to follow the sign als transmittcd from printer 13. Any number of sending relays may be inserted in the circuit` with-their windings in series, to transmit signals to any desired number of division stations or branch receivingstations.

The operation of sending relay 14. in accordance with the signals transmitted by relay 12, will'open and close a circuit traced of relay The armature of relay-l12 bil from positive battery 43 through the ywinding of relay 20, contacts of relay 14, through one side of telegraph channel 18 to ground,47 through the receiving printer 4 8 and one winding of relay 46 at the division headquarters (Fig. 3), operating the receiving printer and causing the armature ofrelay 46 to move to its marking position. The operation of relay 46 (Fi 3) will actuate relay equipment at the division switchboard connected to channel 18 and will cause signals to be automatically transmitted back over the line 18 to opera-te receiving printer 26. This will be described in connection with Fig. 3. As mentioned previously, full duplex, one-way and other repeaters may be inserted into the telegraph channel, if considered desirable.

Relay 20, in releasing, will light lamp 22 as an indication to the operator at the switchboard that signals are being sent to the division station connected to telegraph channel 18.

Key 24 is rovided for short-circuiting the contacts o sending relay 14 to prevent the signals from being transmitted over channel 18. In this manner, the central switchboard may broadcast to a selected few of thev division stations, or to all the divisions as desired.

lt is to be noted that the operator at general headquarters, by watching the lamp indicators or the position of keys 24 and 25, can quickly observe which division stations are connected to receive the broadcast signals. The operation of the receiving set 26 is a visual indication to the central switchboard operator that the apparatus at the division station to which the set is connected is Jfunctioning properly.

Receiving set 26 is also used to receive signals which are initiated at the division switchboard. This will be described in connection with the transmission of signals from a division station.

Telegraph channel 19 connects another division switchboard to the central switchboard. Lamp indicator 23 and receiving set 27 associated with sending relay 15 and telegraph channel 1S) are provided to function in a manner similar to that described for lamp indicator 22 and receiving set 26 associated with sending relay 14. hort-eircuiting key 25 and relay 2l are connected in the circuit in a manner similar to that described for short-circuiting key 24 and relay 20 and serve a similar purpose.

For operating the branch receiving sets 31 and 32, which are local to `the central switchboard, sending relays 16 and 17 and'kcys 37 and 38 are provided. One-way polar repeaters D and D connect the central switchboard with the receiving sets -through telegraph lines 33 and 34. The polar repeaters are well known in the telegraph art and their operation will be described in connection with the transmission of signals to the receiving stai tions- To condition repeater D for transmitting, key 37 is operated. This willremove shortcircuitin ground 30 from the marking contact of re ay 16 and will permit the operation of sending relay 16, in accordance with the operation of master relay 12, to correspondingly operate relay 35, on af circuit from ground on the armature and contact of relay 16 to battery through the left winding of relay 35. Relay 35 has two windings, through one of which a biasing current flows. This biasing current normally tends to keep the armature against the left contact. The flow of current Athrough the left winding 'operates relay 35 At this point, it will be noted that in cases 4 where the receiving station is not at a great distance from the switchboard the one-wa polar repeater ma be eliminated. In suc case, battery will e supplied at the contact of relay 16 instead of ground, and key 37 will be inserted in series with the telegra h line 33, with ground 30 removed from t e circuit.

It will be noted that the operator at the central switchboard may transmit to'one or all divisions, and to one or all the receiving sets connected togeneral headquarters by operating the proper keys. This is quite different from the operation of the division slwitchboard, which will now be described.

React/ving broadcasting signals at cli/vision headguarters Returning to the condition previously described wherein sendingr relay 14 operated to its marking position, it will be recalled that the operation of relay 14 operated relay 46 to its marking position and also operate( receiving printer 48 (Fig. 3). Normally the armature of relay 46 is held to its marking contact over a circuit traced from ground 47 (Fig. 3) through the right-hand winding of relay 46, receiving printer 48, telegraph channel 18, marking contact of relay 14, winding of relay 20, to battery 43 (Fig. 2). It will he noted that a small amount of current flows through theI left or biasing Winding` ot relay 46. This current tends to move the armature of relay 46 to its spacing contact but is not of suicient strength to over- 5 releasing relay 12 and sending relays 14, 15,

16 and 17 to their respective spacing contacts.v The release of relay 14 toits spacing contact,

will open' the operating path through the right-hand winding of relay 46 which, in turn, Will move to its spacinfy contact. 0 The movement of the armature o? relay 46 to its spacing contact Will complete a circuit to o erate relay 49 on a path from ground on t e armature and spacing contact of relay 46 to battery through the windin of relay 49. At this point, it will be note that relay 50 is normally operated on a circuit from ground on the armature and break contact of relay 49 to battery through the Winding of relay 50. Therefore, the operation of relay 49 will cause the release of relay 50. A circuit Will non7 be completed to operate counting relay 51 on a path i' rom ground on the armature of relay 49 through the contacts Yof relays 49, 50, 59 and 52 to battery through the Winding of relay 51, operating relay 51. At this time spring 11 of code key 7 Will have left the insulated bushing 10 and again made contact with the key to reoperate relay 12 and move the armature of relay 12 to the marking contact. This will operate sending relay 14 (Fig. 2) to its marking contact, in turn operating relay 46 to its marking contact. The operation of relay 46 will open the operating path for relay 49 which will release and cause the reoperation of relay 50. At this time counting relay 52 will operate and lock up on a path from battery through the windings of relays 51 and 52, in series, t0 ground through the contacts of relays 51 and 59. VVDhen spring 11 of code key touches insulated bushing 100 to transmit another break signal, an open circuit Will again occur over chann el 18 which will again release relay 46 to its spacing contact. s mentioned before relay 49 Will operate and relay 50 will release. A circuit will now be completed to operate counting relay 53 from ground on the armature of relay 49 through the contacts of relays 49, 50, 59,J 52 and 54 to battery through the Winding of relay 53 operating relay 53. Code key 7 will now return to normal and spring 11 Will again make contact with the key, thus actuating master relay 12 to itsmarking contact and causing a closure of the circuit over channel 18. This last closure will cause the operation of relay 46 to its marking contact, the subsequent release of relay 49, and the reoperation of relay 50. Counting relay 54 will now operate on a circuit from batte-ry through the windings of relays 53 and 54, in series, to ground through the contacts of relays 53 and'59. The operation of relay 54 will place ground on the winding of relay 59 causing it to operate on a circuit traced from groundon the make contact of relays 54 through the Winding of relay 59 to battery on the break Contact of relay 58. Relay 59 Will now lock up on ground through vits right make contact. The operation of relay 59 will remove ground from the windings of counting relays 51, 52, 53 and 54 which will release, the operation of relay A59-Wil1 also cause the operation of relays 60 and 61 on a circuit traced from battery on the left make contact of relay 59 to ground through the windings of relays 60 and 61 in series. The operation of relay 61 will disconnect sending and receiving printer 62 'from the circuit and connect the armature of relay 46 to the upper Winding of master relay 63. Master relay 63 operates to actuate individual sending relays 64, 65 and 66 in the same manner as heretofore described in connection with master relay l2 of Fig. 2. 'The operation of relay 60 will remove the shortcircuiting ground on key 67 from the contact of relay 65 and will permit relay 68 to fol-l low the operations of sending relay 65. The operation of the polar repeater set D from the sending relay is similar to that herein described in connection with the operation of polar repeater D of Fig. 2. Incidentally, it Will be noted that the operation of relay 61 placed a ground on lamp indicator 70 as an indication to the operator at the division sta` tion that general headquarters has taken control of the' station for broadcasting.

Broadcasting from the central switchboard may now take place.

Receiving set 48 at the division switchboard will record the messages received from the central board. Relay 46 Will follow all signals, in turn, operating relay 49 and master relay 63. Relay 63 Will automatically retransmit all incoming signals to the sending be s message signals actuating relay 49. Relay 64 Will operate in response tothe operation of relay 63 and will open and close a circuit traced from battery 45 through the Winding of rela 72, contact of relay 64, telegraph channely 18, receiving printer 26 to ground 44. Receiving set 26 will respond to these signals. In this 'manner the central board will receive the retransmitted message from the division stations While broadcasting to the latter.

Relay 72 will light lamp 71, in accordance with the signals retransmitted by sending relay 64, in a manner hereinbefore described in connection with rela 20 and lamp 22 in Fig. 2.

It will be apparent that there may be many more Sending relays in series With relays 65 and 66 and, also, more line relays in series. with line relay 60, if the number of receiving stations desired Warrant the addition.

It is to be noted that the central switchrelays 64, 65 and 66. Relay 50 is designed to ow in releasing and will not follow the board may seize control of the circuitl at any time and disconnect sending and receiving printer 62 from the master relay 63. Also,

or broadcasting from the central switch- I board to receiving sets local to the `division switchboard, key 67, individual to each local branch receivin set, need not be thrown.

The operation o relay 60 serves the purpose of conditioning the one-way olar repeater ceivmg sets.

After broadcasting a message, general headquarters may send a disconnect signal to restore the circuit to normal by again operating code key 7 forone revolution.

The first break si la 46 to its spacing contact. The release of re ay 46 will operate relay 49 in turn, causing the release of relay 50. ounting relay 55 will then operate from a circuit traced from battery through the winding of relay 55 to ground through the break contact of counting relay 56 and make contacts of relays 59, 50 and 49. When spring 11 leaves bushing 10 and again makes contact on key 7, relay 46 will operate, in turn, releasing` relay 49. The release of rela 49 will cause the operation of relay 50. ountin relay 56 will now operate and lock up on a clrcuit from battery through the windings of relays 55 and 56, in series, to round through make conltact of counting re ay 55, and break contact and armature of counting relay 52. The next break signal transmitted as spring 11 reaches bushing 100 will release relay 46, in turn operating relay 49 and causing the release of relay 50, in a manner similar to that previously described.

Uounting relay 57 will now operate from battery through its winding to round over the break contact of counting re a 58, make contact of counting relay 56, ma e contact of relay 59, break contact of relay 50, make contact and armature of relay 49. When spring 11 returns to its normal position after leaving insulated bushing 100, relay 46 will operate, in turn releasing relay 49 and operating rela 50. Counting relay 58 will now operate an lock up from battery through the windings of counting relays 57 and 58, in series, to ground through the make contact of relay 57 and break contact of relay 52. The operation of counting relay 58 will o en the operating path for relay 59 by removing battery from the winding of relay 59. Relay 59 will therefore release, in turn, releasing relays 60 and 61. The release of relay 6l will connect sending and receiving rinter 62 to the upper Winding of relay 63 t us restoring the circuit to normal. It will be noted that counting relays 55, 56, 57 and 58 will re,- main locked up until general headquarters broadcasts again. When this occurs, the op- 65 eration of counting relay 52 will remove for transmitting signals tot e branch re al transmitted, as spring 11 touches bushing 10, will release reaground from the lockri u circuit and relays Sending from d'vz'sz'on switchboard If the division station desires to transmit to its own local branch receivin stations, sendin printer 62 is utilized. Re ay 63 will be un er the control of printer 62 and vwill function to actuate sending relays 64, 65 and 66 in the same manner as that described in connection with receiving signals from gen` eral headquarters.

The operation of relay 64 will transmit the message back over telegraph channel 18 by operatlng receiving printer 26 at the central switchboard.

In order to transmit to the local receiving station 69, key 67 must be manually operated. 95 The operation of key 67, removes ground on the swinger of the key from the left Winding of relay 68 and permits the latter to follow the operations of 65. The operation of relay 68, in accordance with the operation of sending relay 65, causes the signals to be retransmitted to receiving set 69. 'It is to be understood that the circuit description for transmitting to receivin set 69 applies as well to the o eration of al? other receiving sets con- 10| necte to the division switchboard.

Although only one sending and receiving printer is shown at the central and division switchboards, it is understood, of course, that other sending and receiving printers may be provided for use when a printer set becomes disabled.

What is claimed is:

1. A printin telegraph system of the type used for broa casting messages from a central station to a lurality of remote stations, said remote statlons in turn rebroadcasting the messages to a plurality of branch stations local to each remote station characterized in this,A that the remote stations are normally not in condition to rebroadcast messages received by them and that a special circuit arrangement is utilized at the remote stations for conditioning apparatus at said stations for automatically rebroadcasting, said circuit 126 arrangement being responsive to code signals from said central station. 4

2. A switchboard for transmitting signals to a plurality of stations comprising a relay, counting relay me'ans responsive to signals 130 from said relay and circuit means responsive to the operation of said counting relay means for conditioning the switchboard for transmitting signals to a plurality of branch stations.

i 3. A rinting telegraph system comprising a switchboard, a plurality of .local switchboards, a pluralit of branch receiving stations for each switch ard, a plurality'of telegraph lines connecting the branch receiving stations with each switchboard, a telegraph channel individual to each local switchboard for connecting the local switchboard with the central switchboard, circuit means at each local switchboard responsive to a code signal broadcast from the central switchboard for retransmitting message signals simultaneously to the branch stations.

4. A printing telegraph system in accordance with claim 3, characterized in this, that means are provided at each local switchboard for automatically transmitting back to the central switchboard over the tele raph channel individual to each respective ocal board,

, the message signals received :trom said central switchboard.

5'. A printing telegraph system comprising a central switchboard, a local switchboard connected to said central switchboard, branch receiving stations associated with said local board, circuit means at said local board, said circuit means being responsive to a code signal from said central switchboard for conditioning said local switchboard to retransmit automatically to said branch receiving stations the message signals received from said central switchboard.

6. A radial switching system comprising a central switchboard, a local switchboard, a plurality of outlying branch stations connected to the local switchboard, a telegraph channel connecting said central board with said local board, a telegraph printer at said local switchboard for transmittn messages from the local switchboard to the ranch stations connected thereto, circuit means in said local board responsive to signals from said central board `for seizing control of said local switchboard from said telegraph rinter for broadcastin messages from said central switchboard? l 7. A printin telegraph system comprising a switchboar another switchboard connected thereto, receiving sets associated with said second switchboard, relay means and circuit means at said second board, said relay means being responsive to signals from said iirst board for conditioning said circuit means to retransmit to the receiving sets the message signals received from said first board. y

8. In a printing telegraph system having a central station, a plurality of remote stations, branch stations connected to said remote stations, means at said central station for transmitting signals to any or all of said remote stations, said remote stations being normally not in condition to rebroadcast messages transmitted from said central station, transmitting mechanism at each of the remote stations for transmitting signals to said branch station, circuit means at each of the remote stations under the control of the operator at the central station for disconnecing the transmitting mechanism thereat, in combination with a visual indicator controlled by the disconnection of the transmitting mechanism for indicating to the operator thereat that his transmitter is disconnected.

9. In a printing tele raph system having a central station, a pluraIitv of remote stations,

branch stations connected to said remote stations said remote' stations being normally not in conditidn to rebroadcast messages transmitted from said central station, transmitting mechanism at each of the remote stations circuit means at the remote stations under the control of the operator at the central station for disconnecting the transmitting mechanism thereat, inv combination with an indicating device at the control station controlled by the rebroadcasting of signals from a remote station to indicate that the remote station is rebroadcastin v In testimony whereo I have signed my name to this specification this 20th day of June, 1930.

DONALD B. PERRY.

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